Procedural textures not showing in Material view
Unfortunately, as far as I know, this is not possible at the moment.

I do find myself quite often wishing this was possible, but I am afraid it is not.  the closest thing is, as Bithur said in the comments, you can use Shift+Z to activate rendered viewport mode.

I have heard that the devs are working on adding this support, I have no idea when it is projected to come out though.